Air diffuser fire damper

ABSTRACT

A fire damper apparatus for use with a ceiling mounted air distributor or diffuser. The fire damper is held in the inoperative position against the urging of torsion springs by fusible pins. Melting of the pins allows the damper to rotate into the operative position.

United States Patent [191 McNabney et al.

[451 Jan. 15, 1974 AIR DIFFUSER FIRE DAMPER Inventors: John C. McNabney; Gerhard J.

Hantke, both of La Crosse, Wis.

Assignee: The Trane Company, La Crosse,

Wis.

Filed: Mar. 24, 1972 Appl. No.: 237,786

US. Cl 98/40 D, 49/7, 98/86, 137/74 Int. Cl E051 15/20, F24f 13/06 Field of Search 98/40 D, l, 86; 49/3, 7; 137/74 References Cited UNITED STATES PATENTS Schach 98/40 D 3,601,033 8/1971 Lambert 98/40 D 3,687,055 8/1972 Dean, Jr. 98/40 D 1,078,361 11/1913 Lawrence 49/7 3,396,652 8/1968 Morrison et a1. 98/86 X Primary Examiner-Wi11iam E. Wayner Attorney-Arthur 0. Andersen et a1.

[5 7] ABSTRACT A fire damper apparatus for use with a ceiling mounted air distributor or diffuser. The fire damper is held in the inoperative position against the urging of torsion springs by fusible pins. Melting of the pins'allows the damper to rotate into the operative position.

4 Claims, 8 Drawing Figures PATENTED JAN I 51974 SHEET 1 BF 3 FIG.

FIG. 8

PATENTED JAN] 5 I974 FIG 2 FIG. 3

FIG. 4

AIR DIFFUSER FIRE DAMPER BACKGROUND OF THE INVENTION Specially designed dampers that are intended to open or close in the event of an uncontrolled fire have been suggested for certain types of air handling equipment. Thus ventilator devices that normally admit outside air frequently employ some type of shut-off device to stop the flow of air into the building in case of fire.

More recently, designers have sought to enhance room appearance and space availability by choosing heating, ventilating and air conditioning systems and equipment wherein the air handling units are as unobtrusive as possible. Accordingly, false or suspended ceilings have gained popularity. In the typical suspended ceiling installation, air distributing terminal units are largely concealed in the plenum between the false ceiling and the actual ceiling, with only a small slot or other similar outlet form being visible from the room below.

Building codes generally require that suspended ceilings meet certain fire codes. When the ceiling includes slot openings from the air terminal unit, it is important that some provision be made to close the slots in the event of fire as the diffuser slots represent an open space between the room and the ceiling plenum.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a device for closing air diffuser slots in the event of fire.

A further object of the invention is to provide a fire damper device that is simple and inexpensive to manufacture and install.

Other objects and advantages of the instant structure will become apparent as the specification proceeds.

The present invention provides a fire damper assembly adapted for installation in a slot type air diffuser. The assembly includes at least one damper blade held in an inoperative position by a fusible pin. Upon melting of the pin, the damper blade is rotated into an operative position under the influence of a torsion spring.

DESCRIPTION OF PREFERRED EMBODIMENTS The apparatus will be explained in further detail by reference to the accompanying drawings in which:

FIG. 1 is an exploded perspective view of an air diffuser and fire damper assembly,

FIG. 2 is a side view, partially cut away, of an air diffuser with fire damper assembly installed,

FIG. 3 is an end view, partially cut away, of the air diffuser of FIG. 2,

FIG. 4 is a section view taken along line 44 in FIG. 2,

FIG. 5 is a section view taken along line 5-5 in FIG. 3, l

FIG. 6 is a section view taken along line 66 in FIG.

FIG. 7 is a section view similar to FIG. 6 but with the fire dampers in the closed position, and,

FIG. 8 is an end view, partly in crosssection, showing a slightly modified form of the apparatus.

The major components of the present apparatus include an air diffuser assembly indicated generally at 10 and a fire damper assembly'indicated generally at 30. In FIG. 1 the end panel 12 of diffuser 10 has been removed in order to more clearly show the slot construcchannels are arranged in back-to-back, spaced apart relationship defining a linear slot 22 therebetween. Apertures 24 are provided in the vertical portion of channels l8 and 20, these apertures positioned so as to receive tabs 32 on mounting brackets 34 of the damper assembly 30. An air inlet port 26 is provided at the top portion of box 14 through which conditioned air is re ceived from a duct or control unit, the conditioned air being distributed to the space to be conditioned through slot 22.

The fire damper assembly 30 may include an inverted U-shaped center portion 36 having horizontal projections 38. The projections 38 cooperate with channels 18 and 20 when assembly 30 is installed to provide for air diffusing slots 22a and 22b. Fixed to center portion 36 are mounting brackets 34, which can be used in any convenient numberaccording to the length of the slot 22. Each mounting bracket has a hole 40 drilled in its top center portion through which a cotter pin 42 may be passed. Dampers 44 are provided with flange portion 46 which are similarly drilled to receive cotter pins 42. Springs 48 are mounted coaxially on cotter pin 42 in the center portion of dampers 44. It will be understood that if desired, similar springs could be employed at the location of the cotter pins at each end of damper 44. Springs 48 are of the torsional type, that is, fingers 50 are loaded so as to tend to rotate about the longitudinal axis of the spring, the finger at one end of the coil tending to rotate clockwise the finger at the opposite end of the coil tending to rotate counterclockwise. Accordingly, when dampers 44 are rotated to the upward position, as shown for example in FIG. 1, springs 48 are biased such that they will cause dampers 44 to rotate about cotter pins 42 to the horizontal position in the absence of a restraining force.

Dampers 44 are held in the upward or open position by wires 52 which pass through aperture 53 and restrain dampers 44 against the force exerted by springs 48. Wires 53 are made of a fusible material, preferably a fusible metal such as an alloy of lead and tin, although many other specific materials may suggest themselves to those skilled in the art.

Damper assembly 30 is inserted into place in air diffuser assembly 10, and is held in place by engagement of tabs 32 into apertures 24. The tabs may be bent over for secure installation. Dampers 44 are held in the vertical position by wires 52. The air diffuser assembly is generally installed in a false ceiling type of installation with the assembly being supported on gridwork (not shown) which is engaged by notches 13 in end panels 12. Ceiling tile or the like is installed on the gridwork with the tiles adjacent the diffuser assembly fitting into the open portions of channels 18 and 20. In such an installation, only slot 22 will be exposed to the room below the false ceiling.

In the event of a fire in the room it is desirable to close off slot 22 for each diffuser to prevent the fire from spreading through the fire resistant suspended ceiling. Accordingly, the heat from the fire causes wires 52 to melt, allowing springs 48 to rotate about the spring axis, in turn rotating dampers 44 about the coaxial cotter pins 42, the dampers being urged to a horizontal, closed position as illustrated in FIG. 7.

While the apparatus has generally been shown and described in terms of a double center slot type of diffuser having slots 22a and 22b, and therefore two dampers 44, FIG. 8 illustrates another form to be used with a single slot diffuser. It can be seen that the construction of the fire damper assembly 30 remains unchanged except for the fact that only one damper 44 and one wire 52 is necessary to cover the single slot 22.

In other respects,.the structure is comparable to that shown in FIGS. 1-7.

It can be seen that the present structure provides an effective fire damper apparatus that is of simple and economical construction. The damper assembly can be assembled into the loaded configuration and easily inserted into the slot diffuser structure. As such, the apparatus can be easily adapted for installation and application in a variety of known slot type of air diffusers.

While the present apparatus has been described in detail for purposes of clarity, it will be understood that many modifications can be made by those skilled in the art without departing from the spirit of the invention, and that the scope of the invention is to be measured by the appended claims.

We claim:

1. An air diffusing apparatus adapted for installation in a suspended ceiling construction, said apparatus including an air receiving portion having an air inlet and an air outlet, said air outlet including first and second channel members, said channel members being spaced apart to form an air discharge slot therebetween, a plurality of vertical support members disposed in said slot and connected to said channel members; at least one damper blade operably connected to said support members by means of pin fastening means, said pin fastening means providing a rotational axis for said damper blade; at least one torsion spring in operative engagement with said damper blade; a fusible element cooperating with at least one of said support members and said damper blade, whereby said damper blade is rotated to a closed position relative to said air discharge slot by the force of said spring upon destruction of said fusible member.

2. The apparatus of claim 1 wherein said torsion spring is coaxially mounted on one of said pin fastening means.

3. The apparatus of claim 1 including an inverted U- shaped member connected to said vertical support members and running lengthwise of said slot whereby said slot is subdivided into two parallel diffusing slots.

4. The apparatus of claim 3 having two damper blades operably connected to said support members, each damper blade adapted to close one of said parallel diffusing slots. 

1. An air diffusing apparatus adapted for installation in a suspended ceiling construction, said apparatus including an air receiving portion having an air inlet and an air outlet, said air outlet including first and second channel members, said channel members being spaced apart to form an air discharge slot therebetween, a plurality of vertical support members disposed in said slot and connected to said channel members; at least one damper blade operably connected to said support members by means of pin fastening means, said pin fastening means providing a rotational axis for said damper blade; at least one torsion spring in operative engagement with said damper blade; a fusible element cooperating with at least one of said support members and said damper blade, whereby said damper blade is rotated to a closed position relative to said air discharge slot by the force of said spring upon destruction of said fusible member.
 2. The apparatus of claim 1 wherein said torsion spring is coaxially mounted on one of said pin fastening means.
 3. The apparatus of claim 1 including an inverted U-shaped member connected to said vertical support members and running lengthwise of said slot whereby said slot is subdivided into two parallel diffusing slots.
 4. The apparatus of claim 3 having two damper blades operably connected to said support members, each damper blade adapted to close one of said parallel diffusing slots. 